How to Choose the Right Pet Urn Size
Pet urn sizing explained: the one-cubic-inch-per-pound rule, a weight-to-volume chart in kg and lb, and what to do when your pet falls between two sizes.
Urn size is the one decision in this process that cannot be undone later, and it is the one people most often get wrong. The good news is that the rule behind it is simple.
The one rule you need
One cubic inch of urn capacity for every pound your pet weighed in life.
That is the standard the whole industry works to, and it holds regardless of species or breed. A 40 lb dog needs an urn of roughly 40 cubic inches.
It sounds arbitrary. It is actually generous — cremated remains take up far less volume than the living animal, and the ratio builds in comfortable headroom so nothing has to be forced.
In metric, the working version is 1 kg of body weight ≈ 55 ml of capacity.
The chart
| Size | Diameter | Pet weight | Capacity | Typical breeds |
|---|---|---|---|---|
| S | 8 cm | up to 10 kg / 22 lb | ~22 in³ / 360 ml | Cats, rabbits, guinea pigs, Chihuahua, Pomeranian |
| M | 10 cm | 10–20 kg / 22–44 lb | ~44 in³ / 720 ml | Shiba Inu, Corgi, Beagle, Cocker Spaniel, French Bulldog |
| L | 13 cm | 20–40 kg / 44–88 lb | ~88 in³ / 1,440 ml | Labrador, Golden Retriever, Border Collie, German Shepherd |
Our full size guide has the same chart with more breed examples.
Use their healthy weight, not their last weight
This is the part that catches people.
Many animals lose a significant amount of weight in their final months, particularly with kidney disease, cancer or simply old age. If you size the urn against the weight on the last vet invoice, you may end up short.
Use the weight your pet was when they were well — the number you would have given a boarding kennel a few years ago. If you genuinely do not know, breed averages are close enough.
If you already have the ashes
Easier. The crematorium paperwork usually states the volume, or you can weigh the sealed bag: cremated remains are roughly 1 lb per 500 ml of volume.
Send us either number and we will tell you which size fits. This takes us thirty seconds and removes all the guesswork.
Between two sizes? Go up.
Every time.
An urn slightly larger than needed looks like an urn. An urn slightly too small is a problem you discover at the worst possible moment, with no way to fix it and a four-week wait for a replacement.
The visual difference between our M and L is 3 cm of diameter. Nobody who receives the larger one has ever mentioned it.
If you are only keeping a portion
A lot of people scatter most of the ashes somewhere meaningful and keep a small amount at home. Others divide them between family members.
In that case size S is almost always enough, whatever the breed — a token amount rather than the full volume. Our smaller keepsakes are built for exactly this.
What about two pets in one urn?
Add the weights together and size against the total. We have made a number of these for pairs who lived their whole lives together, usually with both figurines on the lid. Mention it when you order so we plan the lid composition properly.
A note on our sizes specifically
Our measurements describe the spherical body of the jar, not including the figurine on the lid. A size M urn stands taller than 10 cm once the sculpture is on it — worth knowing if you are measuring a shelf.
Still unsure? Send us your pet’s weight and we will tell you which size we would make. It costs nothing to ask, and it is a difficult thing to change afterwards.
